Generally, bicycles are used for a variety of purposes, e.g., leisure, sports, means of transportation, etc.
Particularly, in recent years, as the number of people who use bicycles for commuting increases, and environmental improvement of residential areas is resulting in an increase of the number of bike lanes or parks which permit bicycle traffic, the distribution rate of bicycles has been on the rise.
Bicycles typically include a bicycle frame provided with a saddle, a front wheel, a rear wheel, pedals provided in the bicycle frame to allow a rider to push them with his or her feet to rotate them, sprockets respectively provided on the pedals and the rear wheel, and a chain that connects the sprockets to each other to transmit the rotating force from the pedal to the rear wheel.
If the rider sits on the saddle and pedals, the rotating force of the pedals, in other words, the drive force, is transmitted to the rear wheel by the chain, thus propelling the bicycle.
The height of the saddle has been able to be adjusted manually.
However, the manual method of adjusting the height of the saddle requires a lot of force or use of a separate tool when handling related elements, thus inconveniencing the user. Further, it takes a lot of time, and it is impossible to adjust the height of the saddle when the bicycle is traveling.